In a large-scale wireless local area network (WLAN) scenario such as high-density venues and metros, within a short time period, a large quantity of mobile terminals request access to a WLAN or roam on a WLAN, and therefore large-scale concurrent events are caused. A large quantity of access points (AP) are usually configured on a WLAN on which there are a large quantity of stations (STA). To reduce difficulty in maintaining a large quantity of STAs, a WLAN controller may be configured to centrally perform configuration management on these APs. After receiving an association request sent by a STA, an AP sends the association request to the WLAN controller for processing. Therefore, the large-scale concurrent events severely affect a processing capability of the WLAN controller on the WLAN.
Due to a limitation on central processing unit (CPU) load of the WLAN controller, the WLAN controller can process limited requests per unit time, and a large quantity of mobile terminals need to wait a relatively long time before accessing the WLAN.